Husqvarna 25rl trimmer not starting on pull cord

[trooper1954]

Hi,
I have an older trimmer that has a priming bulb. After lots of primes it will not start, until I put a few drops of gas into the cylinder. When I pull the plug it looks light grey....I suspect that the priming bulb is not priming because of an air leak....I think around the grommet that goes into the tank.
Would this cause these symptoms?
Thank you.

 

[hlw49]

No, it would have to have a hole in the fuel line or a bad check valve in the carburetor. If it runs after you put the fuel in the cylinder it would not be a hole in the fuel line.

 

[Auto Doc's]

Hello hlw49,

Does it seem to run normal at high speed once started?

Is the choke actually working? The primer is only made to purge excess air from the fuel lines and not to shoot fuel into the carburetor throat.

This does favor like a bad carburetor check valve or a stiff pulse diaphragm. Attempting a rebuild for this problem is next to impossible and only aftermarket carburetors are available unless you get lucky on Ebay and find a new old stock carburetor.

It could be the fuel quality also. I have had a rash of Hardware store and Walmart purchased premixed canned tru-fuel problems lately.

(If you mix your own fuel, even it needs to be fresh to support cold start combustion.)

Some customers buy this canned pre-mix fuel and think it will last forever. Once the new can is open, air is introduced. Then letting it sit in a hot storage building just makes it worse because fuel oxidizes and has what is known as phase separation with all the additives.

 

[StarTech]

It takes someone familiar with these rotary barrel carburetors to repair them and I have repaired a lot of them. Usually non start is the metering diaphragm being stiff not opening the metering needle. Primers can go bad but that is fairly rare.